How to make the "Related to" column in Calls module Listview a sortable column

In a listview of all Calls, the "Related To" column is not sort-able like all the other columns. When a call is logged we relate the call to the Account which does show in the listview. However in order to see all the calls sorted in alphabetical order by the "related to" column you would need to "sort" it and there is no icon to sort the "Related To" column.

We have an existing feature request asking for this function. I attempted to make a change to the file system directly to set the "Related To" field as sortable, but the result was not the expected behavior. Specifically, the file was:

/custom/modules/Calls/metadata/listviewdefs.php

I set the "PARENT_NAME" to sortable => 'true';

sortable => 'true';

I then ran a Quick Repair & Rebuild. However, when I refreshed the Calls listview and sorted against the "Related To" field, no results returned until I reset my user preferences.